why does dwObject_merge() discard some objects

We’re merging tracked & detected objects (as described in the Development Guide). Looking at the first frame in one of our videos, we have 72 car detections being merged with 0 previously tracked objects (since it’s the first frame). The result of the merge is 22 objects. Given the limited descriptions in the API documentation and Development Guide, I would have expected the merge to yield 72 objects in this example.

Does anyone know whether there’s a threshold of some sort that’s used by dwObject_merge() to discard incoming objects altogether?


Dear petexklxv,
May I know the Driveworks version? Can you quickly check detections in the first list and tracked outputs in the second and let us know?

Hi SivaRamaKrishna,

For #1, our DriveWorks version is 0.6.67.

For #2, I’m not sure what you’re asking. I provided some details about what we were feeding to the merge (0 tracked, 72 merged) and what we are getting out (22 total). What other details are you looking for?


Dear petexklxv,

Temporary solution: It looks like the detections should be the first list and tracked outputs should be the second. Otherwise, the objects are merged within the same list.

The documentation will be fixed or the logic will change. I’ll take a look at this. Thanks.

Dear petexklxv,
In dwObject_object() parameters, Can you check if you are passing first dwObject list as tracker list and second DwObject list as detections list?